The ability to reduce the surface tension of water is important for waterborne coating formulations as decreased surface tension leads to enhanced substrate wetting particularly for hydrophobic surfaces. Static- and dynamic surface tension are important measures of the ability of a wetting agent to reduce surface tension in aqueous systems.
Traditional nonionic surfactants, such as alkylphenol or alkyl ethoxylates and ethylene oxide (EO)/propylene oxide (PO) copolymers, and anionic surfactants, such as sodium dialkyl sulfosuccinates, exhibit acceptable static surface tension properties. However, many of these surfactants create foam, which can lead to surface defects, poor adhesion, and processing difficulties.